Ultrasonography versus computed tomography for suspected nephrolithiasis

Genitourinary Ultrasound

Renal and genitourinary (GU) complaints are common reasons for presentation to the emergency department (ED). This article reviews the approach to renal, bladder, and testicular point-of-care ultrasound (POCUS) with specific discussions of commonly encountered ED pathology. It presents algorithms highlighting the clinical integration of renal and GU POCUS into the evaluation and management of these patients.

Patient satisfaction using handheld ultrasound at emergency department in Jordan University Hospital

INTRODUCTION

The use of portable ultrasound equipment in emergency medicine has shown the capacity to greatly improve patient care in the swiftly changing field. This research evaluates the influence of the Butterfly POCUS device on patient contentment in the Emergency Department at Jordan University Hospital.

MATERIALS AND METHODS

We conducted a cross-sectional survey of 98 patients to examine their satisfaction levels after undergoing an ultrasound examination. We then evaluated these levels in relation to demographic and clinical characteristics.

RESULTS

Seventy eight percent of the patients expressed a high level of satisfaction with their evaluation. This satisfaction level was consistent across all patient demographics, with no notable differences. Significantly, there was a clear correlation between greater satisfaction levels and higher first pain ratings, indicating that the technology effectively addresses patient concerns and enhances the diagnostic experience.

CONCLUSION

The findings of our study support the wider use of portable ultrasound technology in emergency care settings, emphasizing its ability to greatly enhance patient satisfaction and outcomes. Further investigation should include multicenter trials to authenticate these results and investigate the long-term effects on clinical practice.

Renal and Genitourinary Ultrasound Evaluation in Emergency and Critical Care: An Overview

Renal and genitourinary ultrasound are fundamental resources employed by emergency and critical care healthcare providers to make prompt diagnoses and perform ultrasound-guided procedures. At the bedside, ultrasound can aid in the diagnosis of relevant pathologies, such as post-renal obstruction or kidney stones, and life-threatening conditions such as aortic dissection or hemoperitoneum. A narrative overview was performed, providing an updated review of renal and genitourinary ultrasound for emergency and critical care healthcare providers, emphasizing its advantages and the latest advances in the field. A thorough summary that can be utilized as a guide for emergency and critical care healthcare providers is presented. The daily hemodynamic management of critically ill patients involves the implementation of new protocols, such as VexUS or the evaluation of the renal resistance index. The role of ultrasound in managing acute nephropathy and genitourinary issues is increasingly crucial given its bedside availability, thus this imaging modality not only facilitates the initiation of therapeutic interventions but also provides swift prognostic insights that are vital to provide tailored patient care. As further advances in ultrasound will arise, it is important for healthcare providers to foster the use of these technologies capable of improving patient outcomes.

Combined action observation and mental imagery versus neuromuscular electrical stimulation as novel therapeutics during short-term knee immobilization

Limb immobilization causes rapid declines in muscle strength and mass. Given the role of the nervous system in immobilization-induced weakness, targeted interventions may be able to preserve muscle strength, but not mass, and vice versa. The purpose of this study was to assess the effects of two distinct interventions during 1 week of knee joint immobilization on muscle strength (isometric and concentric isokinetic peak torque), mass (bioimpedance spectroscopy and ultrasonography), and neuromuscular function (transcranial magnetic stimulation and interpolated twitch technique). Thirty-nine healthy, college-aged adults (21 males, 18 females) were randomized into one of four groups: immobilization only (n = 9), immobilization + action observation/mental imagery (AOMI) (n = 10), immobilization + neuromuscular electrical stimulation (NMES) (n = 12), or control group (n = 8). The AOMI group performed daily video observation and mental imagery of knee extensions. The NMES group performed twice daily stimulation of the quadriceps femoris. Based on observed effect sizes, it appears that AOMI shows promise as a means of preserving voluntary strength, which may be modulated by neural adaptations. Strength increased from PRE to POST in the AOMI group, with +7.2% (Cohen's d = 1.018) increase in concentric isokinetic peak torque at 30°/s. However, NMES did not preserve muscle mass. Though preliminary, our findings highlight the specific nature of clinical interventions and suggest that muscle strength can be independently targeted during rehabilitation. This study was prospectively registered: ClinicalTrials.gov NCT05072652.

Types of Evidence Needed to Assess the Clinical Value of Diagnostic Imaging

AbstractThe evidence underlying the use of advanced diagnostic imaging is based mainly on diagnostic accuracy studies and not on well-designed trials demonstrating improved patient outcomes. This has led to an expansion of low-value and potentially harmful patient care and raises ethical issues around the widespread implementation of tests with incompletely known benefits and harms. Randomized clinical trials are needed to support the safety and effectiveness of imaging tests and should be required for clearance of most new technologies. Large, diverse cohort studies are needed to quantify disease risk associated with many imaging findings, especially incidental findings, to enable evidence-based management. The responsibility to minimize the use of tests with unknown or low value requires engagement of clinicians, medical societies, and the public.

Exploring the potential of combined B-mode features and color Doppler ultrasound in the diagnosis of ureteric stone as an alternative to ionizing radiation exposure by computed tomography

OBJECTIVE

To assess the diagnostic efficacy of integrating B-mode and color Doppler capabilities of ultrasound (US) to establish a robust standalone diagnostic tool for the diagnosis of ureteric stones as an alternative to non-contrast-enhanced computed tomography (NCCT).

METHODS

A total of 140 consecutive patients diagnosed with ureteric stones using NCCT were enrolled. On the same day, US in both B-mode and Color Doppler was performed by an experienced radiologist who was blinded to the NCCT scan results. The diagnostic rate of US for stone detection was recorded. Additionally, baseline patient and stone characteristics were analyzed for their association with the accuracy of stone detection using US.

RESULTS

US exhibited a high sensitivity of 91.43%, detecting 128 out of 140 stone foci. Notably, ureteric stones in the proximal and uretero-vesical junction (UVJ) segments were readily identifiable compared to those in the pelvic region (p = 0.0003). Additionally, hydronephrosis enhanced the US's ability to detect stones (p < 0.0001). Conversely, abdominal gases and obesity adversely affected US capabilities (p < 0.0001 and p = 0.009, respectively). Stone side, size, and density showed no statistically significant impact (p > 0.05).

CONCLUSIONS

US with its color Doppler capabilities could serve as a reliable and safe alternative imaging modality in the diagnostic work up of patients with ureterolithiasis. Factors including stone location, Hydronephrosis, weight and abdominal gases significantly influenced its accuracy.

Obstructive uropathy: Overview of the pathogenesis, etiology and management of a prevalent cause of acute kidney injury

Obstructive uropathy is defined as the structural or functional interruption of urinary outflow at any level in the urinary tract. It is regarded as one of the most prevalent causes of acute kidney injury (AKI), accounting for 5%-10% of cases. Acute severe obstruction of the urinary tract is a potentially threatening situation for the kidneys and therefore requires prompt identification and management to relieve obstruction. The aim of the present article is to review and synthesize available evidence on obstructive uropathy, providing a clinical guideline for clinicians. A literature review on obstructive uropathy in the context of AKI was performed, focusing on the least clarified aspects regarding diagnosis and management. Recent literature searching was conducted in English and top-level evidence articles including systematic reviews, metanalyses and large series were prioritized. Acute obstruction of the urinary tract is a diagnostic and therapeutical challenge that may lead to important clinical complications together with direct structural and hemodynamic damage to the kidney. Early recognition of the leading cause and its exact location is essential to ensure prompt urinary drainage together with the most suitable drainage technique selection. A multidisciplinary approach, including urologists, nephrologists, and other medical specialties, is best suited to correctly manage concomitant hemodynamic changes, fluid and electrolyte imbalances, and other related issues. Obstructive uropathy is one of the leading causes of AKI. Recognition of patients suitable for early diversion and feasibility or adequate selection of the indicated technique is sometimes challenging. A thorough understanding of the physiopathology behind the development of urinary obstruction is vital for correct diagnosis and management.

Recurrent Urinary Stone Formers: Imaging Assessment and Endoscopic Treatment Strategies: A Systematic Search and Review

Background/Objectives: Nephrolithiasis is a heterogeneous disease with a high prevalence and recurrence rate. Although there has been much progress regarding the surgical treatment of stones, a standardized follow-up, especially in recurrent stone formers (SFs), has yet to be decided. This fact leads to the overuse of computed tomography (CT) scans and many reoperations in patients, thus increasing their morbidity and the financial burden on the health systems. This review systematically searched the literature for original articles regarding imaging strategies and endoscopic treatment for patients with recurrent urolithiasis, aiming to identify optimal strategies to deal with these patients. Methods: We systematically searched the Medline database (accessed on 1 April 2024) for articles regarding imaging modalities and endoscopic treatment for patients with recurrent urinary tract lithiasis. Results: No specific follow-up or endoscopic treatment strategy exists for patients with recurrent urolithiasis. CT scan was the imaging modality most used in the studies, followed by X-ray, ultrasonography, and digital tomosynthesis. A transparent algorithm could not be identified. Percutaneous nephrolithotomy (PCNL), retrograde intrarenal surgery (RIRS), and ureteroscopy (URS) were used in the studies for endoscopic treatment. PCNL showed the best stone-free (SFr) rate and lowest hazard ratio (HR) for reoperation. RIRS showed superiority over extracorporeal shockwave lithotripsy for recurrent SFs, but fragments over 4 mm increased the recurrent rate. URS has an increased HR for reoperation for bilateral stones. Conclusions: The heterogeneity of urolithiasis leaves urologists without a standardized plan for recurrent SFs. Thus, each patient's follow-up should be planned individually and holistically. Pre-stenting is not to be avoided, especially in high-risk patients, and SFr status needs to be the aim. Finally, CT scans should not be generally overused but should be part of a patient's treatment plan. Prospective studies are required to define SFr status, the size of significant residual fragments, and the modalities of intervention and follow-up.

[Renal colic]

INTRODUCTION

Renal colic accounts for 5-10% of all emergency department visits, making it a common condition in acute medicine. The typical clinical presentation is an early indication of urolithiasis.

DIAGNOSIS

Diagnostic measures include laboratory tests, ultrasound, and low-dose noncontrast computed tomography (CT) scans. Kidney, ureter, bladder (KUB) plain film radiography has been widely replaced by low-dose noncontrast CT with similar radiation dosage. In special patient groups such as children or pregnant women, ionizing radiation should be avoided if possible.

TREATMENT

General measures involve pain management (non-steroidal anti-inflammatory agents, opioids) and empirical antibiotic treatment for suspected bacterial infection. Depending on the location/size of the stone, pharmacological stone expulsion therapy may be considered. In cases of obstructive pyelonephritis or acute renal insufficiency, early urinary drainage (JJ stent/nephrostomy) is recommended. Definitive stone removal may be performed primarily in some cases (rather small and rather distal ureterolithiasis). It is common to schedule stone removal as a secondary intervention.

Urolithiasis diagnosed with endovaginal ultrasound after vaginal prolapse repair surgery using mesh: A case report

Pain after vaginal prolapse repair surgery with mesh is generally attributed to the mesh fixation, particularly to mesh erosion, dislocation or the development of hematoma. However, once all the causes have been excluded, the urinary system, bladder and ureters should be accurately examined by means of endovaginal ultrasound. This report concerns the case of a 72-year-old woman who had undergone mesh-supported prolapse surgery 3 months prior, with no other relevant diseases, who visited the emergency department complaining of dull, right-sided colic pain. The endovaginal ultrasound examination revealed a prevesical ureteral calculus on the right side with consequent dilatation of the proximal ureter. Computed tomography of the abdomen and pelvis confirmed the calculus in the distal right ureter and revealed a right renal lower pole calculus. The patient underwent treatment via an operative ureterorenoscopy with removal of stones and placement of a double-J-stent. Two months later, a second ureterorenoscopy was performed with double-J-stent removal and concomitant stone extraction. It appears that no similar cases have been reported in the literature. This is why, during the urogynecological postoperative follow-up, it is of paramount importance to examine the entire urogenital system with endovaginal ultrasound. This case report highlights how, through a simple, non-invasive, radiation-free examination, like ultrasound, most of the post-operative complications of vaginal prolapse repair surgery using mesh, including urolithiasis, can be excluded.

Dual-Responsive and Aggregation-Induced-Emission Probe for Selective Imaging of Infectious Urolithiasis

Identifying infected stones is crucial due to their rapid growth and high recurrence rate. Here, the calcium-magnesium dual-responsive aggregation-induced emission (AIE)-active probe TCM-5COOH (Tricyano-methlene-pyridine-5COOH), distinctively engineered to distinguish high-threat infection calculi from metabolic stones, is presented. Upon incorporation of flexible alkyl carboxyl group, TCM-5COOH featuring five carboxyl moieties demonstrates excellent water solubility and enhanced penetration into porous infectious stones. The robust chelation of TCM-5COOH with stone surface-abundant Ca2+ and Mg2+ inhibits vibrational relaxation, thus triggering intense AIE signals. Remarkably, the resulting complex exhibits high insolubility, effectively anchoring within the porous structure of the infection calculi and offering prolonged illumination. Jobs' plot method reveals similar response characteristics for Ca2+ and Mg2+, with a 1:2 coordination number for both ions. Isothermal titration calorimetry (ITC) results demonstrate higher enthalpy change (ΔH) and lower entropy change (ΔS) for the reaction, indicating enhanced selectivity compared to TCM-4COOH lacking the alkyl carboxyl group. Synchrotron X-ray absorption fine spectroscopy (XAFS) validates TCM-5COOH's interaction with Ca2+ and Mg2+ at the microlevel. This dual-responsive probe excels in identifying infectious and metabolic calculi, compatible with endoscopic modalities and laser excitation, thereby prompting clinical visualization and diagnostic assessment.

Prevention, diagnosis, and treatment of urolithiasis in geriatric patients - differences, similarities and caveats in comparison to the general population

PURPOSE OF REVIEW

Purpose of the review is to address management and prevention of urolithiasis in elderly patients examining the dynamic interplay between general measures, dietary adjustments, lifestyle modifications, and targeted pharmacological and/ or surgical interventions. The goal is to provide understanding of the evolving strategies required for effective urolithiasis prevention in the geriatric population.

RECENT FINDINGS

Age-specific diagnostic considerations are necessary because urolithiasis in the elderly population is characterized by bigger stones, greater peri-operative risks, and heightened symptom severity. When comorbidities are present, conservative treatments - especially analgesia - provide difficulties. Surgical procedures prove to be safe and effective, with complication rates and practical application comparable to younger cohorts. Prevention approaches that include lifestyle changes and the investigation of novel pharmaceutical options such as sodium-dependent glucose co-transporter 2 (SGLT-2)-inhibitors are promising in the management of urolithiasis in the elderly population.

SUMMARY

Our review offers a thorough investigation of urolithiasis in the elderly population, elucidating distinct clinical manifestations, complex diagnostic issues, and treatment implications. The safety and effectiveness of ureteroscopy in older patients, as well as the possible prophylactic function of SGLT-2-I, offer crucial insights for clinicians. Subsequent studies are necessary to enhance age-specific therapies, addressing the distinct obstacles presented by urolithiasis in the elderly population within this rapidly growing demographic.

Determining the Stone Free Rate of Retrograde Intrarenal Surgery. Which Radiological Technique? RIRSearch Study Group

OBJECTIVE

To evaluate the sensitivity and specificity of ultrasonography (USG) and kidney ureter bladder radiography (KUB) for the determination of stone-free status of retrograde intrarenal surgery (RIRS) according to different stone-free status definitions.

MATERIALS AND METHODS

The patients who underwent RIRS between September 2021 and September 2022 were prospectively included in the study. All patients underwent a KUB radiography, urinary system USG and noncontrast abdominal tomography at the postoperative first month of the surgery. The sensitivity, specificity, negative predictive factor, and positive predictive factor of USG and KUB on evaluating the stone-free rate were analyzed according to different stone-free status definitions.

RESULTS

A total of 178 patients were included in the study. The stone-free rates according to stone-free definitions as; residual stone <4 mm, <2 mm and no residual stone were 79.2%, 64.0%, and 56.7%, respectively. According to its definition as a residual stone <4 mm, the sensitivity and specificity of USG were 64.9% and 84.3%, respectively. The sensitivity of USG was 57.1% and 52.5% as the definitions were residual stone <2 mm and no residual stone, respectively. Addition of KUB to USG slightly increased the sensitivity but did not change the specificity.

CONCLUSION

USG had high specificity but low sensitivity for evaluating stone-free status after RIRS and addition of KUB did not increase the diagnostic efficacy. Although USG may be used in daily practice, it may overestimate the stone-free status and noncontrast abdominal tomography must be used during the clinical trials to document the exact stone-free rates of RIRS.

Ultrasonography of acute retroperitoneum

The retroperitoneum is an important space in the human body that is often implicated in a range Epub ahead of print of acute medical conditions, some of which can be life-threatening. Ultrasonography may serve as a pivotal first-line imaging technique when assessing patients with suspected retroperitoneal abnormalities. Effective ultrasonography of the retroperitoneum requires a comprehensive grasp of its anatomy, adjacent structures, and potential pathologies. Being well-acquainted with the imaging characteristics of acute conditions can meaningfully assist in an accurate diagnosis and guide subsequent management. This review article summarizes and illustrates the acute conditions involving the retroperitoneum through the lens of ultrasound imaging.

Point-of-care ultrasound associated with shorter length of stay than computed tomography for renal colic

BACKGROUND

Despite similar diagnostic effectiveness for renal colic, computed tomography (CT) is more resource intensive than point-of-care ultrasound (PoCUS). We sought to compare Emergency Department (ED) length of stay (LOS) among patients with renal colic according to imaging modality utilized. We secondarily compared rates of infection, return ED visits, missed significant pathology, and urologic intervention.

METHODS

This was a 12-month (1/1/22-12/31/22) multi-site retrospective cohort study of all patients diagnosed with renal colic who presented to the ED on days when at least one patient had a billable renal PoCUS examination performed. Patients with a history of genitourinary malignancy, pregnancy, renal transplant, hemodialysis, single kidney, prior visit for renal colic in the previous 30 days, or an incomplete workup were excluded. Median ED LOS was compared using a Wilcoxon rank sum test, and the 95% confidence limits for the difference between medians was calculated. Secondary outcomes were compared using a Fisher's Exact test.

RESULTS

Of 415 patients screened, 325 were included for analysis: 150 had CT alone, 80 had PoCUS alone, 54 had PoCUS plus CT, and 41 had neither. Median LOS for PoCUS alone was 75.0 (95% CI 39.3-110.7) minutes shorter than CT alone (231.5 vs. 307.0 min, p < 0.0001). Similar rates of infection, return visits, and missed pathology occurred across all groups (p > 0.10). Urologic interventions were higher in the PoCUS plus CT (25.9%) group compared to CT alone (7.3%), PoCUS alone (2.5%), and neither (7.3%), p < 0.0001.

CONCLUSION

Among patients with renal colic, PoCUS was associated with shorter ED LOS compared to CT, without differences in infection rates, return visits, or missed pathology. Patients with PoCUS plus CT had a higher rate of urologic interventions, suggesting PoCUS may have a role in identifying patients who would most benefit from CT.

Harnessing Artificial Intelligence for Enhanced Renal Analysis: Automated Detection of Hydronephrosis and Precise Kidney Segmentation

Background and objective

Hydronephrosis is essential in the diagnosis of renal colic. We automated the detection of hydronephrosis from ultrasound images to standardize the therapy and reduce the misdiagnosis of renal colic.

Methods

Anonymously collected ultrasound images of human kidneys, both normal and hydronephrotic, were preprocessed for neural networks. Six "state of the art" models were trained and cross-validated for the detection of hydronephrosis, and two convolutional networks were used for kidney segmentation. In the testing phase, performance metrics included true positives, true negatives, false positives, false negatives, accuracy, and F1 score, while the evaluation of the segmentation task involved accuracy, precision, dice, jaccard, recall, and ASSD.

Key findings and limitations

A total of 523 sonographic kidney images (423 nonhydronephrotic and 100 hydronephrotic) were collected from three different ultrasound devices. After training on this dataset, all models were used to evaluate 200 new ultrasound kidney images (142 nonhydronephrotic and 58 hydronephrotic kidneys). The highest validation accuracy (98.5%) was achieved by the AlexNet model (GoogLeNet 97%, AlexNet_v2 96%, ResNet50 96%, ResNet101 97.5%, and ResNet152 95%). The deeplabv3_resnet50 and deeplabv3_resnet101 reached a dice coefficient of 94.74% and 94.48%, respectively, on the task of automated kidney segmentation. The study is limited by analyzing only hydronephrosis, but this specific focus enabled high detection accuracy.

Conclusions and clinical implications

We show that our automated ultrasound deep learning model can be trained and used to interpret and segmentate ultrasound images from different sources with high accuracy. This method will serve as an automated tool in the diagnostic algorithm of acute renal failure in the future.

Patient summary

Hydronephrosis is crucial in the diagnosis of renal colic. Recent advances in artificial intelligence allow automated detection of hydronephrosis in ultrasound images with high accuracy. These methods will help standardize the diagnosis and treatment renal colic.

Machine learning models for screening clinically significant nephrolithiasis in overweight and obese populations

PURPOSES

Our aim is to build and evaluate models to screen for clinically significant nephrolithiasis in overweight and obesity populations using machine learning (ML) methodologies and simple health checkup clinical and urine parameters easily obtained in clinics.

METHODS

We developed ML models to screen for clinically significant nephrolithiasis (kidney stone > 2 mm) in overweight and obese populations (body mass index, BMI ≥ 25 kg/m2) using gender, age, BMI, gout, diabetes mellitus, estimated glomerular filtration rate, bacteriuria, urine pH, urine red blood cell counts, and urine specific gravity. The data were collected from hospitals in Kaohsiung, Taiwan between 2012 and 2021.

RESULTS

Of the 2928 subjects we enrolled, 1148 (39.21%) had clinically significant nephrolithiasis and 1780 (60.79%) did not. The testing dataset consisted of data collected from 574 subjects, 235 (40.94%) with clinically significant nephrolithiasis and 339 (59.06%) without. One model had a testing area under curve of 0.965 (95% CI, 0.9506-0.9794), a sensitivity of 0.860 (95% CI, 0.8152-0.9040), a specificity of 0.947 (95% CI, 0.9230-0.9708), a positive predictive value of 0.918 (95% CI, 0.8820-0.9544), and negative predictive value of 0.907 (95% CI, 0.8756-0.9371).

CONCLUSION

This ML-based model was found able to effectively distinguish the overweight and obese subjects with clinically significant nephrolithiasis from those without. We believe that such a model can serve as an easily accessible and reliable screening tool for nephrolithiasis in overweight and obesity populations and make possible early intervention such as lifestyle modifications and medication for prevention stone complications.

Pathophysiology and Main Molecular Mechanisms of Urinary Stone Formation and Recurrence

Kidney stone disease (KSD) is one of the most common urological diseases. The incidence of kidney stones has increased dramatically in the last few decades. Kidney stones are mineral deposits in the calyces or the pelvis, free or attached to the renal papillae. They contain crystals and organic components, and they are made when urine is supersaturated with minerals. Calcium-containing stones are the most common, with calcium oxalate as the main component of most stones. However, many of these form on a calcium phosphate matrix called Randall's plaque, which is found on the surface of the kidney papilla. The etiology is multifactorial, and the recurrence rate is as high as 50% within 5 years after the first stone onset. There is a great need for recurrence prevention that requires a better understanding of the mechanisms involved in stone formation to facilitate the development of more effective drugs. This review aims to understand the pathophysiology and the main molecular mechanisms known to date to prevent recurrences, which requires behavioral and nutritional interventions, as well as pharmacological treatments that are specific to the type of stone.

Diagnostic accuracy of Point Of Care UltraSound (POCUS) in clinical practice: A retrospective, emergency department based study

AIMS

Point-of-care ultrasound (POCUS) is the acquisition and interpretation of ultrasound imaging at the bedside to solve specific clinical questions based on signs and symptoms of presentation. While several studies evaluated POCUS diagnostic accuracy for a variety of clinical pictures in the emergency department (ED), only a few data are available on POCUS diagnostic accuracy performed by physicians with different POCUS skills. The objective of this research was to evaluate the diagnostic accuracy of POCUS compared to standard diagnostic imaging in the ED.

MATERIALS AND METHODS

This was a retrospective study conducted in the ED of a third-level university hospital. Patients who underwent cardiac, thoracic, abdominal, or venous lower limb POCUS and a standard imaging examination between June 2021 and January 2022 were included.

RESULTS

1047 patients were screened, and 844 patients included. A total of 933 POCUS was included (102, 12.09%, cardiac; 466, 55.21%, thoracic; 336, 39.8%, abdominal; 29, 3.44%, lower limb venous POCUS), accounting for 2029 examinations. POCUS demonstrated 96.6% (95% CI 95.72-97.34) accuracy, 47.73 (95% CI 33.64-67.72) +LR, 0.09 (95% CI 0.06-0.12) -LR. +LR was greater than 10 for all investigations but for hydronephrosis (5.8), and -LR never exceeded 0.4.

CONCLUSIONS

POCUS exhibited high diagnostic accuracy for virtually all conditions when performed by emergency department physicians.

Radiological Explorations of Patients with Upper or Febrile Urinary Tract Infection

Recent European Association of Urology (EAU) guidelines and a clinical prediction rule developed by Van Nieuwkoop et al. suggest simple criteria for performing radiological imaging for patients with a febrile urinary tract infection (UTI). We analysed the records of patients with a UTI from four hospitals in Switzerland. Of 107 UTI patients, 58% underwent imaging and 69% (95%CI: 59-77%) and 64% (95%CI: 54-73%) of them were adequately managed according to Van Nieuwkoop's clinical rule and EAU guidelines, respectively. However, only 47% (95%CI: 33-61%) and 57% (95%CI: 44-69%) of the imaging performed would have been recommended according to their respective rules. Clinically significant imaging findings were associated with a history of urolithiasis (OR = 11.8; 95%CI: 3.0-46.5), gross haematuria (OR = 5.9; 95%CI: 1.6-22.1) and known urogenital anomalies (OR = 5.7; 95%CI: 1.8-18.2). Moreover, six of 16 (38%) patients with a clinically relevant abnormality displayed none of the criteria requiring imaging according to Van Nieuwkoop's rule or EAU guidelines. Thus, adherence to imaging guidelines was suboptimal, especially when imaging was not recommended. However, additional factors associated with clinically significant findings suggest the need for a new, efficient clinical prediction rule.

Test characteristics of point-of-care ultrasonography in patients with acute kidney injury

BACKGROUND

Acute kidney injury is a common disorder that is associated with significant morbidity and mortality. Point-of-care ultrasonography (PoCUS) is an imaging modality performed at the bedside and is used to assess for obstructive causes of acute kidney injury. Little is known about the test characteristics of PoCUS in patients with acute kidney injury.

OBJECTIVE

Our primary objective was to describe the test characteristics of PoCUS for the detection of hydronephrosis in patients presenting with acute kidney injury at our centre. Our secondary objective was to describe the current rate of use of PoCUS for this indication.

RESULTS

In total, 7873 patients were identified between June 1, 2019 and April 30, 2021, with 4611 meeting inclusion criteria. Of these, 94 patients (2%) underwent PoCUS, and 65 patients underwent both PoCUS and reference standard, for a total of 124 kidneys included in our diagnostic accuracy analysis. The prevalence of hydronephrosis in our cohort was 33% (95% CI 25-41%). PoCUS had a sensitivity of 85% (95% CI 71-94%) and specificity of 78% (95% CI 68-87%) for the detection of hydronephrosis.

CONCLUSION

We describe the test characteristics of PoCUS for the detection of hydronephrosis in a cohort of patients with acute kidney injury. The low uptake of this test presents an opportunity for quality improvement work to increase its use for this indication.

Assessing Diagnostic Performance

Assessing Diagnostic PerformanceDiagnosis is an action and a goal in medicine. This article is the introduction to a series of review articles on varying facets of diagnosis. Clinical diagnosis is an exercise in classification; that is, placing the patient's condition in the correct diagnostic category. However, consideration must also be given to the performance objective, whether it is technical performance of a test, acquiring diagnostic information with respect to clinical management for an individual or a population's health outcomes, or cost-effectiveness and equity of care.

Ultrasound accuracy in evaluating renal calculi in Maysan province

Renal calculi are a common clinical presentation. While ultrasound (US) is a widely used imaging modality for kidney stone diagnosis due to its accessibility and lower cost, its accuracy compared to computerized tomography (CT), the gold standard, remains understudied. This cross-sectional study evaluated the diagnostic accuracy of ultrasound for detecting and characterizing kidney stones compared to computed tomography (CT). Fifty-six patients with suspected kidney stones based on flank pain underwent abdominal ultrasound to assess stone presence, size, location, and the severity of any hydronephrosis (kidney swelling). These findings were then confirmed with a subsequent non-contrast CT scan. There was a fair agreement between US and CT (Kappa = 0.368) for detecting the stone location. The US could not detect 7 (12.5%) stones, being less sensitive in the middle and upper calyx compared to CT. There was a fair agreement between the US and CT (Kappa = 0.394) for detecting the severity of hydronephrosis. The US was less sensitive to moderate and severe hydronephrosis compared to CT. The abdominal ultrasound demonstrated excellent reliability for stone size measurement (intraclass correlation = 0.924), with CT measurements only slightly larger on average (mean difference 0.9 mm). Although abdominal ultrasound provides reliable stone size assessment, its capacity to accurately localize stones and assess hydronephrosis severity is limited.

Utilization of Point-of-Care Ultrasound as an Imaging Modality in the Emergency Department: A Systematic Review and Meta-Analysis

Point-of-care ultrasound (POCUS) is an imaging modality that has become a fundamental part of clinical care provided in the emergency department (ED). The applications of this tool in the ED have ranged from resuscitation, diagnosis, and therapeutic to procedure guidance. This review aims to summarize the evidence on the use of POCUS for diagnosis and procedure guidance. To achieve this, CrossRef, PubMed, Cochrane Library, Web of Science, and Google Scholar databases were extensively searched for studies published between January 2000 and November 2023. Additionally, the risk of bias assessment was performed using the Quality Assessment of Diagnostic Accuracy Studies 2 (for studies on the diagnostic role of POCUS) and Cochrane Risk of Bias tool (for studies on the use of POCUS for procedure guidance). Furthermore, diagnostic accuracy outcomes were pooled using STATA 16 software (StatCorp., College Station, TX, USA), while outcomes related to procedure guidance were pooled using the Review Manager software. The study included 81 articles (74 evaluating the diagnostic application of POCUS and seven evaluating the use of POCUS in guiding clinical procedures). In our findings sensitivities and specificities for various conditions were as follows: appendicitis, 65% and 89%; hydronephrosis, 82% and 74%; small bowel obstruction, 93% and 82%; cholecystitis, 75% and 96%; retinal detachment, 94% and 91%; abscess, 95% and 85%; foreign bodies, 67% and 97%; clavicle fractures, 93% and 94%; distal forearm fractures, 97% and 94%; metacarpal fractures, 94% and 92%; skull fractures, 91% and 97%; and pleural effusion, 91% and 97%. A subgroup analysis of data from 11 studies also showed that the two-point POCUS has a sensitivity and specificity of 89% and 96%, while the three-point POCUS is 87% sensitive and 92% specific in the diagnosis of deep vein thrombosis. In addition, the analyses showed that ultrasound guidance significantly increases the overall success rate of peripheral venous access (p = 0.02) and significantly reduces the number of skin punctures (p = 0.01) compared to conventional methods. In conclusion, POCUS can be used in the ED to diagnose a wide range of clinical conditions accurately. Furthermore, it can be used to guide peripheral venous access and central venous catheter insertion.

Bedside Ultrasound to Identify and Predict Severity of Dysphagia Following Ischemic Stroke: Human Versus Artificial Intelligence

OBJECTIVE

Dysphagia is a significant ischemic stroke complication that can lead to aspiration. Identification of at-risk patients can be logistically difficult and costly. Researchers investigated whether quantitative ultrasound assessment of hyoid bone movement during induced swallowing would predict failure of videofluoroscopy (VFS) or fiberoptic endoscopic evaluation of swallowing (FEES), as determined by a penetration-aspiration scale (PAS) score. Additionally, ability of a machine learning (ML) algorithm to predict PAS success or failure from real-time ultrasound video recordings was assessed.

METHODS

A prospective, single-blinded, observational pilot study was conducted from June 2019 through March 2020 at a comprehensive stroke center on a convenience sample of patients admitted with diagnosis of acute ischemic stroke undergoing VFS or FEES as part of dysphagia assessment. Researchers performed a midsagittal airway ultrasound during swallowing in patients receiving an objective swallowing assessment by speech language pathologists who were blinded to ultrasound results. Sonologists measured hyoid bone movement, and researchers then constructed an ML algorithm designed for real-time video analysis using a long short-term memory network with an embedded VGG16 convolutional neural network.

RESULTS

Videos from 69 patients were obtained with their respective PAS results. In total, 90% of available videos were used for algorithm training. After training, the ML algorithm was challenged with the 10% previously unseen videos and then compared with PAS outcomes. Statistical analysis included logistic regression and correlation matrix testing on human ultrasound measurements. Cohen's κ was calculated to compare deep learning algorithm prediction with PAS results. Measurement of hyoid bone elevation, forward displacement, total displacement and mandible length was unable to predict PAS assessment outcome (p values = 0.36, 0.13, 0.11 and 0.32, respectively). The ML algorithm showed substantial agreement with PAS testing results for predicting test outcome (κ = 0.79; 95% confidence interval: 0.52-1.0) CONCLUSION: Manual ultrasound measurement of hyoid movement during swallowing in stroke patients failed to predict PAS swallowing results. However, an ML algorithm showed substantial agreement with PAS results despite a small data set, which could greatly improve access to dysphagia assessment in the future.

Guidance for clinical practice using emergency and point-of-care ultrasonography

Owing to the miniaturization of diagnostic ultrasound scanners and their spread of their bedside use, ultrasonography has been actively utilized in emergency situations. Ultrasonography performed by medical personnel with focused approaches at the bedside for clinical decision-making and improving the quality of invasive procedures is now called point-of-care ultrasonography (POCUS). The concept of POCUS has spread worldwide; however, in Japan, formal clinical guidance concerning POCUS is lacking, except for the application of focused assessment with sonography for trauma (FAST) and ultrasound-guided central venous cannulation. The Committee for the Promotion of POCUS in the Japanese Association for Acute Medicine (JAAM) has often discussed improving the quality of acute care using POCUS, and the "Clinical Guidance for Emergency and Point-of-Care Ultrasonography" was finally established with the endorsement of JAAM. The background, targets for acute care physicians, rationale based on published articles, and integrated application were mentioned in this guidance. The core points include the fundamental principles of ultrasound, airway, chest, cardiac, abdominal, and deep venous ultrasound, ultrasound-guided procedures, and the usage of ultrasound based on symptoms. Additional points, which are currently being considered as potential core points in the future, have also been widely mentioned. This guidance describes the overview and future direction of ultrasonography for acute care physicians and can be utilized for emergency ultrasound education. We hope this guidance will contribute to the effective use of ultrasonography in acute care settings in Japan.

Has fluoroless endourology (URS and PCNL) come of age? Evidence from a comprehensive literature review

INTRODUCTION

Radiation via the use of imaging is a key tool in management of kidney stones. Simple measures are largely taken by the endourologists to implement the 'As Low As Reasonably Achievable' (ALARA) principle, including the use of fluoroless technique. We performed a scoping literature review to investigate the success and safety of fluoroless ureteroscopy (URS) or percutaneous nephrolithotomy (PCNL) procedures for the treatment of KSD.

METHODS

A literature review was performed searching bibliographic databases PubMed, EMBASE and Cochrane library, and 14 full papers were included in the review in accordance with the PRISMA guidelines.

RESULTS

Of the 2535 total procedures analysed, 823 were fluoroless URS vs. 556 fluoroscopic URS; and 734 fluoroless PCNL vs. 277 fluoroscopic PCNL. The SFR for fluoroless vs. fluoroscopic guided URS was 85.3% and 77%, respectively (p=0.2), while for fluoroless PCNL vs. fluoroscopic group was 83.8% and 84.6%, respectively (p=0.9). The overall Clavien-Dindo I/II and III/IV complications for fluoroless and fluoroscopic guided procedures were 3.1% (n=71) and 8.5% (n=131), and 1.7% (n=23) and 3% (n=47) respectively. Only 5 studies reported a failure of the fluoroscopic approach with a total of 30 (1.3%) failed procedures.

CONCLUSION

The ALARA protocol has been implemented in endourology in numerous ways to protect both patients and healthcare workers during recent years. Fluoroless procedures for treatment of KSD are safe and effective with outcomes comparable to standard procedures and could become the new frontier of endourology in selected cases.

The role of point-of-care ultrasound in the assessment of pelvic urine leakage and diagnosis of urinoma

BACKGROUND

Urinoma, a rare condition resulting from urine leakage due to trauma to the kidney, bladder, or urethra, is typically diagnosed using enhanced computed tomography urogram with delayed imaging. This report presents two cases of urinoma likely caused by overdistention of the renal pelvis following excessive fluid intake and the presence of a ureteral stone.

CASE PRESENTATION

We present two cases of 36-year-old and 38-year-old patients who presented with flank pain. point-of-care ultrasound (POCUS) played a pivotal role in identifying perinephric fluid in Morrison's space and the splenorenal space, respectively. These ultrasound findings guided further investigations, leading to definitive diagnoses via abdominal pelvic CT scans. Treatment involved prophylactic antibiotics and the successful placement of a double J stent into the renal pelvis over the wire under fluoroscopic guidance, which resulted in significant clinical improvement for both patients.

CONCLUSIONS

This study demonstrates the rare occurrence of urinoma from urolithiasis, the use of POCUS in expediting diagnosis and treatment, and the importance of interpreting sonographic images in the correct clinical setting.

Utility of ultrasound in managing acute medical conditions in space: a scoping review

BACKGROUND

In long-distance spaceflight, the challenges of communication delays and the impracticality of rapid evacuation necessitate the management of medical emergencies by onboard physicians. Consequently, these physicians must be proficient in tools, such as ultrasound, which has proven itself a strong diagnostic imaging tool in space. Yet, there remains a notable gap in the discourse surrounding its efficacy in handling acute medical scenarios. This scoping review aims to present an updated analysis of the evidence supporting the role of ultrasound in diagnosing acute conditions within microgravity environments.

METHODS

A systematic search was executed across three bibliographic databases: PubMed, EMBASE (Embase.com), and the Web of Science Core Collection. We considered articles published up to February 25, 2023, that highlighted the application of ultrasound in diagnosing acute medical conditions in either microgravity or microgravity-simulated settings. Exclusions were made for review papers, abstracts, and in-vitro studies.

RESULTS

After removing duplicates, and filtering papers by pre-determined criteria, a total of 15 articles were identified that discuss the potential use of ultrasound in managing acute medical conditions in space. The publication date of these studies ranged from 1999 to 2020. A relatively similar proportion of these studies were conducted either on the International Space Station or in parabolic flight, with one performed in supine positioning to simulate weightlessness. The included studies discuss acute pathologies, such as abdominal emergencies, decompression sickness, deep venous thrombosis, acute lung pathologies, sinusitis, musculoskeletal trauma, genitourinary emergencies, and ocular emergencies.

CONCLUSIONS

While ultrasound has shown promise in addressing various acute conditions, significant knowledge gaps remain, especially in gastrointestinal, cardiac, vascular, and reproductive emergencies. As we venture further into space, expanding our medical expertise becomes vital to ensure astronaut safety and mission success.

Prevalence and implications of perinephric fluid on renal point-of-care ultrasound in the emergency department

BACKGROUND

Point-of-care ultrasound (PoCUS) is commonly utilized in the setting of renal colic. The presence of perinephric fluid may be an overlooked finding associated with ureteral obstruction. Our aims were to determine the prevalence of perinephric fluid on emergency physician-performed PoCUS and to determine whether perinephric fluid was associated with stone size or urologic intervention.

METHODS

This was a 12-month cross-sectional study at an academic emergency department (ED) that took place from January 1, 2022, to December 31, 2022. All adult ED patients ≥18 years of age who had a renal PoCUS examination performed were included. Patients with missing or inadequate PoCUS images were excluded. Investigators blinded to PoCUS images and interpretations performed chart review for demographic data and outcome variables, while separate investigators blinded to clinical data reviewed PoCUS images to assess for perinephric fluid and hydronephrosis. A chi-square analysis was used to determine significance of association between perinephric fluid and outcome variables (stone size, urologic intervention).

RESULTS

There were 442 patients screened; 18 were excluded due to inadequate images and 4 were repeat visits of which only the initial visit was analyzed. Of the remaining 420 patients included, the prevalence of perinephric fluid was 6.2% (n = 26). Most patients (23/26) with perinephric fluid had final diagnoses consistent with ureterolithiasis. Hydronephrosis was present in 115 of the 420 patients (27.4%) and of these, 22 (19.1%) had perinephric fluid which was significantly associated with a need for urologic intervention; odds ratio (OR) 10.38 (95% CI 2.70-39.85), p < 0.01. Among the 67 patients with confirmed ureterolithiasis on computed tomography, perinephric fluid was associated with stone size ≥5 mm; OR 4.00 (95% CI 1.01-15.85), p = 0.04.

CONCLUSION

The prevalence of perinephric fluid on emergency physician-performed renal PoCUS was 6.2% of all studies and 19.1% of patients with hydronephrosis. In the setting of ureterolithiasis, perinephric fluid was associated with larger stone size and need for urologic intervention.

POCUS-first for nephrolithiasis: A Monte Carlo simulation illustrating cost savings, LOS reduction, and preventable radiation

OBJECTIVES

Non-contrast computed tomography (NCCT) is the gold standard for nephrolithiasis evaluation in the emergency department (ED). However, Choosing Wisely guidelines recommend against ordering NCCT for patients with suspected nephrolithiasis who are <50 years old with a history of kidney stones. Our primary objective was to estimate the national annual cost savings from using a point-of-care ultrasound (POCUS)-first approach for patients with suspected nephrolithiasis meeting Choosing Wisely criteria. Our secondary objectives were to estimate reductions in ED length of stay (LOS) and preventable radiation exposure.

METHODS

We created a Monte Carlo simulation using available estimates for the frequency of ED visits for nephrolithiasis and eligibility for a POCUS-first approach. The study population included all ED patients diagnosed with nephrolithiasis. Based on 1000 trials of our simulation, we estimated national cost savings in averted advanced imaging from this strategy. We applied the same model to estimate the reduction in ED LOS and preventable radiation exposure.

RESULTS

Using this model, we estimate a POCUS-first approach for evaluating nephrolithiasis meeting Choosing Wisely guidelines to save a mean (±SD) of $16.5 million (±$2.1 million) by avoiding 159,000 (±18,000) NCCT scans annually. This resulted in a national cumulative decrease of 166,000 (±165,000) annual bed-hours in ED LOS. Additionally, this resulted in a national cumulative reduction in radiation exposure of 1.9 million person-mSv, which could potentially prevent 232 (±81) excess cancer cases and 118 (±43) excess cancer deaths annually.

CONCLUSION

If adopted widely, a POCUS-first approach for suspected nephrolithiasis in patients meeting Choosing Wisely criteria could yield significant national cost savings and a reduction in ED LOS and preventable radiation exposure. Further research is needed to explore the barriers to widespread adoption of this clinical workflow as well as the benefits of a POCUS-first approach in other patient populations.

Role of Posterior Acoustic Shadow Width in Ultrasound in Determining Stone Size in Urolithiasis

Introduction Ultrasound (US) is frequently the initial diagnostic tool for urolithiasis, though computed tomography (CT) remains the imaging modality of choice. However, due to potential overestimations, the accuracy of US in gauging stone size has been a point of contention. This study aims to compare the accuracy of stone size measurements in US, specifically evaluating the utility of the posterior acoustic shadow (PAS) width, against the CT measurements. Methods We conducted a cross-sectional study where 120 adult patients (aged >18 years) with confirmed urolithiasis through CT participated. Stone sizes were assessed via both CT and US, with the PAS width also being measured in the latter. Statistical analysis compared stone size discrepancies between both CT and US measurement techniques. Results The study enrolled 73 males and 47 females with various stone locations. The average stone sizes were 15.93 ± 4.59 mm (CT), 18.60 ± 4.80 mm (US), and 16.69 ± 4.61 mm (PAS width). There was a mean difference of 2.67 mm (p < 0.0001) between CT and US sizes, whereas the difference between the PAS width and CT sizes was only 0.75 mm (p = 0.203). Stone size miscalculation by US was 16.77%, whereas it was only 4.77% for PAS width. Conclusion US tends to significantly overestimate stone size when compared to CT. Conversely, the measurement of the PAS width in US presents a more aligned estimation to CT outputs. Integrating PAS width into routine US reporting can enhance the accuracy of stone size estimation, optimizing urolithiasis management and patient counseling.

2022 Recommendations of the AFU Lithiasis Committee: Diagnosis

The choice of imaging modality is guided by the clinical presentation and the context (acute or not). Although ultrasound is safe (no radiation) and easily available, non-contrast-enhanced CT has become the gold standard in the diagnostic strategy for patients with acute flank pain because of its sensitivity (93.1%) and specificity (96.6%). It also allows determining the stone size, volume and density, visualizing their internal structure, and assessing their distance from the skin and the adjacent anatomy. All these parameters can influence the stone management and the choice of intervention modality. METHODOLOGY: These recommendations were developed using two methods: the Clinical Practice Recommendations method (CPR) and the ADAPTE method, depending on whether the issue was considered in the EAU recommendations (https://uroweb.org/guidelines/urolithiasis [EAU Guidelines on urolithiasis. 2022]) and their adaptability to the French context.

Application of ultrasound imaging in the treatment of urinary tract stones

Urinary tract stones are a common clinical condition that affect millions of individuals worldwide. The management of these stones has evolved significantly over the past 70 years, and ultrasound imaging has emerged as a valuable tool for diagnosis, treatment planning, and follow-up. This review aims to provide an overview of the application of ultrasound imaging in the treatment of urinary tract stones, highlighting its advantages, limitations, and current advancements in the field.

Point of Care Ultrasonographic Life Support in Emergency (PULSE)-a quasi-experimental study

BACKGROUND

Many physicians use point-of-care ultrasound (PoCUS) in their clinical practice to improve their diagnostic capabilities, accuracy, and timeliness. Over the last two decades, the use of PoCUS in the emergency room has dramatically increased. This study aimed to determine emergency physicians' retention of knowledge and skills after a brief training workshop on a focused ultrasound-guided approach to a patient presenting with undifferentiated shock, shortness of breath, and cardiac arrest in the emergency department of a tertiary care hospital. The secondary aim was to deliver the PoCUS-guided algorithmic approach to manage a patient presenting with undifferentiated shock, respiratory distress, and cardiac arrest in the emergency department.

METHODS

A quasi-experimental study was conducted with a single-day Point of Care Ultrasonographic Life Support in Emergency (PULSE) training workshop in October 2021 at the Aga Khan University Hospital, Karachi, Pakistan. A total of 32 participants attended the course, including twenty-one junior residents (PGY 1 and 2) and medical officers with experience of fewer than two years working in different emergency departments of urban tertiary care hospitals across Karachi, Pakistan. Pre- and post-assessment tools comprised a written examination, evaluating participants' knowledge and skills in ultrasound image acquisition and interpretation. Cronbach's alpha was used to calculate the validity of the tool. Results obtained before and after the training session were compared by the McNemar's test. A p value of ≤ 0.05 was considered significant.

RESULTS

There was a significant improvement in response to each question pre to post-test after completion of the course (Table 1). The significant change can be seen in questions 7, 8, 13, and 15, with a percentage change of 33.3, 80.9, 42.9, and 47.7. There was a significant improvement in the understanding and knowledge of participants after the training. The scores in the post-test were high compared to the pre-test in each category, i.e., respiratory distress (p < 0.017), cardiac arrest (p < 0.041), basic ultrasound knowledge (p < 0.001), and undifferentiated shock (p < 0.001).

CONCLUSION

All participants showed improvement in their knowledge and confidence regarding using PoCUS in life-threatening conditions. Through this study, we have also developed an algorithmic approach to managing undifferentiated shock, respiratory failure, and cardiac arrest. Future studies must assess the effectiveness and feasibility of incorporating these algorithms into clinical practice.

The Degree of Hydronephrosis as an Indicator of the Necessity for Ureteric Dilatation during Ureteroscopic Lithotripsy

During rigid ureteroscopic lithotripsy, it is often encountered that the ureter is difficult to access. Attempts to advance the ureteroscope make the surgery more difficult. This study evaluated the preoperative predictive factors associated with difficult ureteral access (difficult ureter (DU)) during URS and assessed if clinical outcomes differed according to the degree of DU. This study identified 217 patients who underwent rigid ureteroscopic (URS) lithotripsy for the management of ureter stones between June 2017 and July 2021 in a tertiary hospital in Korea. In this group, preoperative factors were identified using univariate and multiple logistic regression analyses that could predict the degree of DU. Additionally, we also evaluated differences in treatment outcomes depending on the degree of DU. In 50 URS cases (22.0%), ureteral access using a ureteroscope was difficult. In the univariate and multivariate analyses, the degree of hydronephrosis was associated with the degree of DU. Treatment outcomes, extended operation times, low stone-free rate, postoperative pain, and secondary treatment were also significantly associated with the degree of DU. Clinicians can counsel patients with a lesser degree of hydronephrosis and approach their management accordingly.

The Incidence and Risk Factors for Emergency Department Imaging in Acute Renal Colic

Objective: To determine the incidence of and risk factors for imaging in patients presenting to the emergency department (ED) with renal colic. Subject/Patients and Methods: We conducted a population-based cohort study in the province of Ontario, utilizing linked administrative health data. Patients who presented to an ED with renal colic between April 1, 2010, and June 30, 2020, were included. The rate of initial imaging (CT scans and ultrasound [U/S]) and repeat imaging within 30 days was determined. Generalized linear models were utilized to evaluate patient and institutional-level characteristics associated with imaging, and specifically CT vs U/S. Results: There were 397,491 index renal colic events, of which 67% underwent imaging (CT 68%, U/S 27%, and CT+U/S same day 5%). Repeat imaging was performed in 21% of events (U/S in 12.5%, CT in 8.4%) at a median of 10 days. Of those with an initial U/S, 28% had repeat imaging compared with 18.5% for those with an initial CT. Undergoing an initial CT was associated with being male, urban residence, later year of cohort entry, history of diabetes mellitus and inflammatory bowel disease, and presentation to nonacademic hospitals of larger size, or with a higher volume of ED visits. Conclusion: Two-thirds of renal colic patients underwent imaging, and CT was the most utilized modality. Patients undergoing an initial CT had a lower likelihood of repeat imaging within 30 days. The utilization of CT increased over time and was more common in males and those presenting to nonacademic hospitals of larger size, or with higher ED volumes. Our study highlights the patient- and institution-level factors that need to be targeted with prevention strategies to reduce the utilization of CT scans, when possible, for cost reduction and to minimize patient exposure to ionizing radiation.

Identification of Clinically Insignificant Renal Calculi on Sonography

OBJECTIVE

To determine factors predicting if a radiologists... report of a .. stone... on ultrasound (US) was not actually a clinically significant stone, based on subsequent computed tomogram (CT). US often overestimates stone size and various pathologic entities are also hyperechoic;.ßthus, a subsequent CT without a clinically significant stone may represent unnecessary radiation exposure. A decision-tree and nomogram were developed to predict when stones are unlikely on subsequent CT.

METHODS

Retrospective analysis of patients, of any age, receiving CT within 24.ßhours of a sonographic report documenting a single renal stone, during 2019...2020, in any phase of care, at one institution. Novel stone-likelihood-systems for US and CT (US-SLS, CT-SLS) were devised and validated to classify stones as clinically significant or insignificant, with CT as the gold standard. Binomial logistic regression predicting clinically significant stones was performed with sonographic and patient characteristics.

RESULTS

Eight hundred twenty patients had US followed by CT, 228 (27.8%) reported documented stones, 140 (17.1%) reported a single stone. Clinically significant stones were associated with larger stone size (P: .002), location (P: .002), hydronephrosis (P: .04), shadowing-artifact (P: .02) depth.ßto.ßstone (P: .008), and Body mass Index (BMI) (P: .01). US-SLS had higher sensitivity (95.4%) and negative-predictive-value (81.8%) compared to a multivariate model of significant variables.

CONCLUSION

US-SLS appears to exclude clinically irrelevant .. stones... better than established criteria including twinkle or shadow in this retrospective analysis. A diagnostic algorithm and nomogram are presented. US-SLS and the associated decision tree can assist providers in avoiding unnecessary radiation when clinically significant stones are unlikely.

Incidental detection of malignancy on point-of-care renal ultrasound: A case series

Renal point-of-care ultrasound (POCUS) is an increasingly common initial imaging modality in the diagnostic workup of renal colic. The primary use of renal POCUS is to assess for hydronephrosis; however, other significant findings suggestive of malignancy can also be identified. We present three cases of unexpected findings identified initially on POCUS in the emergency department, which subsequently led to new diagnoses of malignancy. As renal POCUS becomes more frequently used in clinical practice, physicians must be able to recognise abnormal images that indicate possible malignancy and the need for further workup.

Value of detected hydronephrosis and hydroureter on ultrasound for detecting a ureteral stone: a retrospective study

To investigate the predictive value of hydronephrosis and hydroureter in the detection of ureteral stones using ultrasound, a total of 366 patients suffering from ureteral stones confirmed by ultrasound, computed tomography (CT) and their follow-up treatments were consecutively collected. All the included patients underwent systematic ultrasound scanning of the kidney and ureter. The hydronephrosis and hydroureter in each patient were measured using a digital caliper. Then, receiver operating characteristic (ROC) curve analysis was used to determine the optimal cutoff values for hydronephrosis and hydroureter to predict a ureteral stone's location and size. The hydronephrosis, hydroureter, and stone size measurements showed good interobserver agreement (P < 0.001). Using the lower border of the sacroiliac joint as a demarcation point, we found larger widths of hydronephrosis and hydroureter in the proximal ureteral stone group than in the distal ureteral stone group (P < 0.001). Additionally, 10.9 mm and 5.9 mm were identified as optimal cutoff values for predicting a distal position (P < 0.001), with no significant difference in their predictive value (P > 0.05). Similar comparisons between groups based on size stratification revealed no significant difference in hydronephrosis between the > 5 mm group and the ≤ 5 mm group. However, the hydroureter was larger in the > 5 mm group than in the ≤ 5 mm group after identifying 6 mm as the best cutoff (P =0.004). In summary, the ultrasound measurement of hydronephrosis and hydroureter may predict the position and size of a possible ureteral stone in patients with colic symptoms.

Point-of-Care Ultrasound (POCUS) Literature Primer: Key Papers on Renal and Biliary POCUS

Objective The objective of this study is to identify the top five influential papers published on renal point-of-care ultrasound (POCUS) and the top five influential papers on biliary POCUS in adult patients. Methods A 14-member expert panel was recruited from the Canadian Association of Emergency Physicians (CAEP) Emergency Ultrasound Committee and the Canadian Ultrasound Fellowship Collaborative. All panel members have had ultrasound fellowship training or equivalent, are actively engaged in POCUS scholarship, and are involved with POCUS at their local site and nationally in Canada. We used a modified Delphi process consisting of three rounds of sequential surveys and discussion to achieve consensus on the top five influential papers for renal POCUS and biliary POCUS. Results The panel identified 27 relevant papers on renal POCUS and 30 relevant papers on biliary POCUS. All panel members participated in all three rounds of the modified Delphi process, and after completing this process, we identified the five most influential papers on renal POCUS and the five most influential papers on biliary POCUS. Conclusion We have developed a list, based on expert opinion, of the top five influential papers on renal and biliary POCUS to better inform all trainees and clinicians on how to use these applications in a more evidence-based manner. This list will also be of interest to clinicians and researchers who strive to further advance the field of POCUS.

Point-of-Care Ultrasound Use in Nephrology: A Survey of Nephrology Program Directors, Fellows, and Fellowship Graduates

Rationale & Objective

Adoption of point-of-care ultrasound (POCUS) into nephrology practice has been relatively slow. We surveyed US nephrology program directors, their fellows, and graduates from a single training program regarding current/planned POCUS training, clinical use, and barriers to training and use.

Study Design

Anonymous, online survey.

Setting & Participants

All US nephrology program directors (n=151), their fellows (academic year 2021-2022), and 89/90 graduates (1980-2021) of the Walter Reed Nephrology Program.

Analytical Approach

Descriptive.

Results

46% (69/151) of program directors and 33% (118/361) of their fellows responded. Response rate was 62% (55/89) for Walter Reed graduates. 51% of program directors offered POCUS training, most commonly bedside training in non-POCUS oriented rotations (71%), didactic lectures (68%), and simulation (43%). 46% of fellows reported receiving POCUS training, but of these, many reported not being sufficiently trained/not confident in kidney (56%), bladder (50%), and inferior vena cava assessment (46%). Common barriers to training reported by program directors were not enough trained faculty (78%), themselves not being sufficiently trained (55%), and equipment expense (51%). 64% of program directors and 55% of fellows reported <10% of faculty were able to perform POCUS. 64% of fellows reported having too little POCUS training. 72% of program directors and 77% of graduates felt POCUS should be incorporated into the fellowship curriculum. 59% of fellows and 61% of graduates desired hands-on POCUS training rather than didactic lectures or simulation.

Limitations

Loss of respondents as program directors and fellows progressed through the survey.

Conclusions

Nephrology program directors, fellows, and graduates surveyed want POCUS training incorporated into the fellowship curriculum. No group felt sufficiently trained to confidently perform POCUS, and the major barrier to training was lack of sufficiently trained faculty. This highlights the need to "train the trainers" before POCUS can be fully integrated into fellowship training and regularly used in nephrology practice.

Detecting Hydronephrosis Through Ultrasound Images Using State-of-the-Art Deep Learning Models

The goal of this study was to assess the feasibility of three models for detecting hydronephrosis through ultrasound images using state-of-the-art deep learning algorithms. The diagnosis of hydronephrosis is challenging because of varying and non-specific presentations. With the characteristics of ready accessibility, no radiation exposure and repeated assessments, point-of-care ultrasound becomes a complementary diagnostic tool for hydronephrosis; however, inter-observer variability still exists after time-consuming training. Artificial intelligence has the potential to overcome the human limitations. A total of 3462 ultrasound frames for 97 patients with hydronephrosis confirmed by the expert nephrologists were included. One thousand six hundred twenty-eight ultrasound frames were also extracted from the 265 controls who had normal renal ultrasonography. We built three deep learning models based on U-Net, Res-UNet and UNet++ and compared their performance. We applied pre-processing techniques including wiping the background to lessen interference by YOLOv4 and standardizing image sizes. Also, post-processing techniques such as adding filter for filtering the small effusion areas were used. The Res-UNet algorithm had the best performance with an accuracy of 94.6% for moderate/severe hydronephrosis with substantial recall rate, specificity, precision, F1 measure and intersection over union. The Res-UNet algorithm has the best performance in detection of moderate/severe hydronephrosis. It would decrease variability among sonographers and improve efficiency under clinical conditions.

CT of the urinary tract revisited

Computed tomography (CT) of the abdomen is usually appropriate for the initial imaging of many urinary tract diseases, due to its wide availability, fast scanning and acquisition of thin slices and isotropic data, that allow the creation of multiplanar reformatted and three-dimensional reconstructed images of excellent anatomic details. Non-enhanced CT remains the standard imaging modality for assessing renal colic. The technique allows the detection of nearly all types of urinary calculi and the estimation of stone burden. CT is the primary diagnostic tool for the characterization of an indeterminate renal mass, including both cystic and solid tumors. It is also the modality of choice for staging a primary renal tumor. Urolithiasis and urinary tract malignancies represent the main urogenic causes of hematuria. CT urography (CTU) improves the visualization of both the upper and lower urinary tract and is recommended for the investigation of gross hematuria and microscopic hematuria, in patients with predisposing factors for urologic malignancies. CTU is highly accurate in the detection and staging of upper tract urothelial malignancies. CT represents the most commonly used technique for the detection and staging of bladder carcinoma and the diagnostic efficacy of CT staging improves with more advanced disease. Nevertheless, it has limited accuracy in differentiating non-muscle invasive bladder carcinoma from muscle-invasive bladder carcinoma. In this review, clinical indications and the optimal imaging technique for CT of the urinary tract is reviewed. The CT features of common urologic diseases, including ureterolithiasis, renal tumors and urothelial carcinomas are discussed.

CT Use Reduction In Ostensive Ureteral Stone (CURIOUS)

INTRODUCTION

Computed tomography (CT) is performed in over 90% of patients diagnosed with ureteral stones, but only 10% of patients presenting to the emergency department (ED) with acute flank pain are hospitalized for a clinically important stone or non-stone diagnosis. Hydronephrosis can be accurately detected using point-of-care ultrasound and is a key predictor of ureteral stone and risk of subsequent complications. The absence of hydronephrosis is insufficient to exclude a stone. We created a sensitive clinical decision rule to predict clinically important ureteral stones. We hypothesized that this rule could identify patients at low risk for this outcome.

METHODS

We conducted a retrospective cohort study in a random sample of 4000 adults who presented to one of 21 Kaiser Permanente Northern California EDs and underwent a CT for suspected ureteral stone from 1/1/2016 to 12/31/2020. The primary outcome was clinically important stone, defined as stone resulting in hospitalization or urologic procedure within 60 days. We used recursive partition analysis to generate a clinical decision rule predicting the outcome. We estimated the C-statistic (area under the curve), plotted the receiver operating characteristic (ROC) curve for the model, and calculated sensitivity, specificity, and predictive values of the model based on a risk threshold of 2%.

RESULTS

Among 4000 patients, 354 (8.9%) had a clinically important stone. Our partition model resulted in four terminal nodes with risks ranging from 0.4% to 21.8%. The area under the ROC curve was 0.81 (95% CI 0.80, 0.83). Using a 2% risk cut point, a clinical decision tree including hydronephrosis, hematuria, and a history of prior stones predicted complicated stones with sensitivity 95.5% (95% CI 92.8%-97.4%), specificity 59.9% (95% CI 58.3%-61.5%), positive predictive value 18.8% (95% CI 18.1%-19.5%), and negative predictive value 99.3% (95% CI 98.8%-99.6%).

CONCLUSIONS

Application of this clinical decision rule to imaging decisions would have led to 63% fewer CT scans with a miss rate of 0.4%. A limitation was the application of our decision rule only to patients who underwent CT for suspected ureteral stone. Thus, this rule would not apply to patients who were thought to have ureteral colic but did not receive a CT because ultrasound or history were sufficient for diagnosis. These results could inform future prospective validation studies.

The Incremental Role of Multiorgan Point-of-Care Ultrasounds in the Emergency Setting

Point-of-care ultrasonography (POCUS) represents a goal-directed ultrasound examination performed by clinicians directly involved in patient healthcare. POCUS has been widely used in emergency departments, where US exams allow physicians to make quick diagnoses and to recognize early life-threatening conditions which require prompt interventions. Although initially meant for the real-time evaluation of cardiovascular and respiratory pathologies, its use has been extended to a wide range of clinical applications, such as screening for deep-vein thrombosis and trauma, abdominal ultrasonography of the right upper quadrant and appendix, and guidance for invasive procedures. Moreover, recently, bedside ultrasounds have been used to evaluate the fluid balance and to guide decongestive therapy in acutely decompensated heart failure. The aim of the present review was to discuss the most common applications of POCUS in the emergency setting.

Diagnostic value ultrasound signs of stones less than or equal to 10 mm and clinico-radiological variants of ureteric colic

Objective

To determine the diagnostic value of ultrasound signs of urinary stones less than or equal to 10 mm and to determine clinico-radiological variants of ureteric colic.

Methods

A total of 455 ultrasound investigations were performed in patients referring to emergency department with urolithiasis and symptoms suspected of ureteric colic between January 2021 and May 2021. In addition to microscopic evaluation of urine sediment to detect different crystals and non-contrast spiral computed tomography to detect stones, B-mode and color Doppler sonography was performed to assess the presence of acoustic shadow (AS) and twinkle artifacts (TA) as possible signs of stone(s) in ureter.

Results

While the sensitivity and specificity of AS and TA were higher than 90% in patients with stones greater than 5 mm; positive prognostic values of these parameters were found to be extremely low for stones with sizes of 1-3 mm with specificity and sensitivity values not exceeding 53%. The sensitivity and specificity of AS and TA in the upper and lower ureters were higher for stones greater than or equal to 5 than for compared to those less than 5 mm. At the same time, the diagnostic values of TA and AS for middle ureter stones were very limited. The most prevalent clinico-radiological variants of ureteric colic were types I, III, and V being observed in 39%, 28% and 21% cases, respectively.

Conclusion

Our results demonstrate that TA and AS parameters seem to have a very low sensitivity and specificity in the diagnosis of urinary stones less than 5 mm. The diagnostic value of TA and AS increase significantly in stones greater than or equal to 5 mm. Therefore, clinicians need to be very careful for overestimating the diagnostic values of TA and AS for stones less than 5 mm and non-contrast spiral computed tomography must be the method of choice for patients presenting to emergency department with ureteric colic.

National Imaging Trends for Suspected Urinary Stone Disease in the Emergency Department

This cohort study examines the use of an ultrasonography-first strategy for urinary stone disease.